The modern gasoline internal combustion engine is designed to operate at both low power (idle) or high power. To achieve this dual design parameter, it is necessary that a variable fuel-air ratio be used. For example, at idle it is necessary that the fuel-air mixture admitted as an inlet charge into the engine combustion chamber be relatively rich and significantly higher than the stoichiometric ratio of 0.067. While at higher power a leaner fuel-air mixture is required.
By admitting these rich mixtures under low power and part throttle operation of the engine there is a tendency to promote exhaust gases that are high in unburned hydrocarbons. These unburned hydrocarbons have a relatively high fuel energy content and can be burned in the engine to provide power that otherwise might be wasted. The underlying principle by which the instant invention operates is that the inventive apparatus allows there unburned hydrocarbons to be efficiently re-introduced into the intake manifold of the engine.
The prior art searched disclosed the following patents that although do not read directly on the invention are nevertheless related:
______________________________________ U.S. PAT. No. INVENTOR ISSUED ______________________________________ 4,279,236 Dallman 21 July 1981 4,237,840 Figueiras 9 December 1980 3,554,174 Clawson 12 January 1971 ______________________________________
The Dallman patent discloses an automotive fuel savings system that incorporates three individual air flow circuits. The first withdraws crankcase vapors and directs them through the air filter into the intake manifold; the second divides an air flow between the crankcase inlet orifice and the air filter; the third directs air into an area below the throttle plate in the carburetor. The three circuits function in combination to provide a crankcase ventilation system that allegedly results in improved engine efficiency and operation.
The Figueiras patent discloses a system for collecting and filtering gases and vapors produced in the exhaust manifold, crankcase transmission casing and the fuel tank of an internal combustion engine. These gases and vapors are then combined with fresh air and the mixture is supplied to the engine together with the fuel-air mixture from the carburetor to improve combustion.
The Clawson patent discloses an induction system for regulating the induction air inlet temperature of an internal combustion engine. Two induction circuits are employed: a throttle controlled ambient air circuit and a second inlet pressure regulated circuit that supplies air at elevated temperatures. The combined effect of the two circuits is to admit air to the engine in quantities that allows a satisfactory engine operation over a wide range at lean fuel-air ratios.